Synthesis of tagged polymers by post-polymerization (trans)amidation reaction

ABSTRACT

Polymers tagged with pendant fluorescent groups are prepared by the (trans)amidation derivatization of pre-existing polymers having carbonyl-type pendant groups. Polymers having pendant amide groups wherein the amide nitrogen is substituted with fluorescent moieties, prepared by (trans)amidation derivatization, are provided. Polymers having pendant (sulfonated) napthalene moieties substituted to amide nitrogen are provided.

This is a division of application Ser. No. 07/569,865, now U.S. Pat. No.5,128,419 filed Aug. 20, 1990.

TECHNICAL FIELD OF THE INVENTION

The present invention is in the technical field of polymer synthesis bythe method of post-polymerization derivatization and polymers preparedthereby. More particularly, the present invention is in the technicalfield of synthesizing polymers having pendant fluorescent groups andpolymers prepared thereby.

BACKGROUND OF THE INVENTION

In many fields that employ polymers it may be desirable to tag or marksuch polymers to facilitate monitoring thereof. By the term "monitoring"is meant herein any type of tracing or tracking to determine thelocation or route of the polymers, and any type of determination of theconcentration or amount of the polymer at any given site, includingsingular or intermittent or continuous monitoring. For instance, it maybe desirable to monitor water treatment polymers in water systems,particularly industrial water systems, or to monitor polymers that maybe present in waste fluids before disposal, particularly industrialwaste fluids, or to monitor the polymer used for down-hole oil wellapplications, particularly the route taken after introduction down-hole,or to monitor polymers that may be present in fluids used to wash amanufactured product, for instance a polymer-coated product, todetermine the amount of polymer washed or leached therefrom. By fluidsor liquids as used herein generally is meant aqueous, non-aqueous, andmixed aqueous/non-aqueous fluid systems. As seen from the above list ofpossible applications of polymer monitoring, the purpose of suchmonitoring may be to trace or track or determine the level of thepolymer itself, or to trade or track or determine the level of somesubstance in association with the polymer, or to determine some propertyof the polymer or substance in association with the polymer, forinstance its leachability.

Conventional techniques for monitoring polymers are generallytime-consuming and labor intensive, and often require the use of bulkyand/or costly equipment. Most conventional polymer analysis techniquesrequire the preparation of calibration curves for each type of polymeremployed, which is time-consuming and laborious, particularly when alarge variety of polymer chemistries are being employed, and theoriginally prepared calibration curves lose their accuracy if thepolymer structures change, for instance an acrylic acid ester mer unitbeing hydrolyzed to an acrylic acid mer unit. Direct methods wherein thelevel of functional groups present in a polymer is determinedanalytically are generally not practical for industrial use,particularly when it is desired to monitor a polymer on a frequent orcontinuous basis, or when rapid monitoring results are needed. Indirectmethods of polymer monitoring may provide more rapid results usingsimpler techniques, but in many instances faster and/or more accuratedeterminations are desirable.

Polymers tagged with pendant fluorescent groups are generally easilymonitored, even when present at low concentrations. Highly fluorescentmolecules, that is molecules which have a fluorescent quantumefficiency, or fluorescent quantum yield, within the range of from about0.1 to about 1.0, and a light absorbance molar extinction coefficient ofat least 1,000, are typically detectable at concentration ranges ofparts per million ("ppm") to parts per billion ("ppb") or even less. Theincorporation of such a highly fluorescent species into a polymer in theamount of one weight percent (based on polymer actives) will permit thedetection of such polymer at polymer concentration levels down to 0.1ppm or less, provided the fluorescent quantum yield and the lightabsorbance molar extinction coefficient of the fluorescent tagging agentare not significantly adversely affected by its attachment to thepolymer.

It would be desirable to provide a method of tagging polymers withpendant fluorescent groups by derivatization of a pre-existing polymerand hence avoid problems such as potential side-reactions or othercomplications that may arise in attempts to incorporate fluorescentmonomer units into the polymer during synthesis of such polymer. Itwould be desirable to provide a method of tagging pre-existing polymerswith pendant fluorescent groups so as to permit polymers that arecommercially available without such tagging to be converted to taggedpolymers. It would be desirable to provide such a method that minimizesthe reaction steps required and minimizes the time required for thereaction. It would be desirable to provide such a method that proceedsunder reaction conditions that do not have a deleterious effect on thepolymer structure. It would be desirable to provide such a method thatcan utilize as the agent providing the pendant fluorescent groups,inexpensive commercially available compositions. It would be desirableto provide such a method that can employ a wide variety of fluorescentderivatizing agents and hence provide tagged polymers having a widevariety of fluorescent spectra, particularly when it is desired tomonitor polymers individually in situations where a plurality ofpolymers are present. For instance, such polymers may be tagged withdistinguishable fluorescent derivatizing agents and hence each polymermay be individually monitored, or the derivatizing agent(s) may beselected so as to monitor the polymer(s) even in the presence of otherfluorescent material(s). It would be desirable to provide such a methodwherein a reasonably high concentration of polymer starting material maybe utilized. It would be desirable to provide such a method that is notdependent on the presence of a single type of pendant group beingpresent on the starting material polymer. It would be desirable toprovide such a method that can proceed simultaneously with otherpost-polymerization derivatizing reactions. It would be desirable toprovide polymers tagged with fluorescent groups produced by such amethod. It would be desirable to provide such polymers having diversefluorescent tags. It would be desirable to provide such polymersderivatized at reasonable cost. It would be desirable to provide suchpolymers having fluorescent spectra distinguishable from the spectra ofthe fluorescent derivatizing agents employed. These and other objectsare provided by the present invention which is described in more detailbelow.

DISCLOSURE OF THE INVENTION

The present invention provides a method of preparing polymers havingpendant fluorescent groups by (trans)amidation derivatization ofpre-existing polymers by reaction between certain pendant groups on suchpolymers and certain organic fluorescent derivatizing agents. Morespecifically, the pendant polymer groups derivatized by the(trans)amidation reaction are carbonyl-type groups of the Formula I:##STR1## wherein R is --OR' or --NH₂, wherein R' is hydrogen or asubstituent other than hydrogen, and salts thereof, and mixtures andcombinations thereof. By salts is meant herein alkali metal salts,alkaline earth metal salts, amine salts, alkanol amine salts, and thelike. By "substituent" is meant herein a single or multivalent groupother than hydrogen covalently bonded to a carbon of an organicmolecule.

The pendant polymer group derivatized by the (trans)amidation reactionmay be contained in a polymer unit or mer unit (a portion of the polymercontaining two adjacent backbone carbons) having the structure ofFormula II: ##STR2## wherein R₄ is C_(n) H_(2n) wherein n is zero or aninteger from 1 to about 10, R₁, R₂ and R₃ are independently hydrogen ora substituent other than hydrogen, and R is as defined above for FormulaI, and salts thereof, and mixtures or combinations thereof.

The organic fluorescent derivatizing agent is an organic fluorescentmolecule that contains an amine group, preferably a primary amine group,Such an agent may be represented by the Formula III: ##STR3## whereinone of R₅ and R₆ may be, and preferably is, hydrogen, and within atleast one of R₅ and R₆ or within R₅ and R₆ together, is an organicfluorescent group. The (trans)amidation derivatization reaction proceedsas follows: ##STR4## wherein the structure designated Formula IV aboveis a (trans)amidation derivatized pendant group on the polymer. As seenfrom Formula IV, the derivatized pendant polymer group is a pendantN-substituted amide group having a fluorescent group within at least oneof R₅ and R₆ or within R₅ and R₆ taken together. This reaction is anamidation reaction when R is --OR' and a transamidation reaction when Ris --NH₂, and hence the term "(trans)amidation" is used herein tospecify either or both forms of the reaction.

PREFERRED EMBODIMENTS OF THE INVENTION

The (trans)amidation reaction is conducted in an aqueous reactionmixture generally, employing a starting material polymer that is watersoluble at the concentration used, or is introduced as held within alatex, and in addition, employing an organic fluorescent derivatizingagent that is water soluble. The reaction mixture preferably is fluid.The product polymer resulting from the (trans)amidation derivatizationreaction may possibly have its solubility characteristics so altered bythe incorporation of the fluorescent group that it precipitates, orpartially precipitates, from the reaction mixture.

The (trans)amidation reaction is conducted at elevated temperatures, andgenerally under pressures that exceed atmospheric pressure. In generalit is desirable not to degrade the polymer to any significant extentduring the derivatization reaction and generally a reaction in a closedvessel at a temperature of from about 120° to about 200° C., for a timeperiod of from about 1 to about 8 hours, may be suitable, the presssurebeing dependent in part on the temperature. In preferred embodiment thereaction is conducted at from about 130° to about 155° C. In preferredembodiment the reaction is conducted over a time period of from about 1to about 6 hours. Nonetheless, the reaction may proceed somewhat attemperatures as low as 75° or 80° C.

The derivatization reaction may be conducted with air present in thereaction vessel at times, but it may be desirable to exclude oxygen, forinstances by purging the reaction vessel with nitrogen gas prior to thereaction. When it is desirable to reduce the pressure that wouldotherwise be attained by reaction at a given temperature, the reactionvessel may have its internal pressure reduced prior to closing andraising the temperature for the transamidation reaction.

The derivatization reaction may be conducted under varying pHconditions, for instance, at a pH of from about 3 to about 10 orpossibly 11, but it is preferable, particularly to avoid hydrolysis orpolymer degradation, to conduct the reaction at a moderate pH. Moreover,one of the advantages of the present invention is that thederivatization reaction proceeds at a moderate pH, which preferably is apH of from about 5 to about 7.

Another of the advantages of the present invention is that, for asuitable polymer starting material, the derivatization reaction may beconducted employing a high concentration of starting material polymer,which is particularly advantageous for the commercial use of thederivatization reaction. Commercially, a starting material polymerconcentration of at least about 10 weight percent is desirable, but if alow water solubility polymer is used, a lower concentration may benecessary to maintain a fluid reaction mixture. For water solublepolymers with weight average molecular weights of up to 50,000 to200,000, or up to 50,000 to 100,000, starting material polymerconcentrations of from about 10 to about 45 weight percent aredesirable, and from about 30 to about 45 weight percent are verypreferred.

As noted above, the starting material polymer may be a polymercontaining polymer units of the Formula II above. Such polymer units maybe derived from acrylic acid, wherein the n of R₄ is zero, each of R₁,R₂ and R₃ are hydrogen, and R is --OH. Such polymer units may be derivedfrom acrylamide, similar to acrylic acid except R is --NH₂. Such unitsmay be methacrylic acid or methacrylamide wherein R₂ is methyl, or forinstance itaconic acid wherein R₂ is --CO₂ H, R₄ is --CH₂ --, and R is--OH. Such polymer units may contain carboxylic acid esters, such asmethylacrylate wherein R is --OR' and R' is methyl. It is believed thatexisting N-substituted amide pendant groups do not to any significantextent participate in the (trans)amidation reaction.

The presence of nonparticipating pendant groups on the starting materialpolymer generally will not interfere with the (trans)amidation reaction,and hence the present invention may be used to tag a wide variety ofpre-existing polymers.

Only a very low level of fluorescent groups need to be incorporated intoa polymer to provide fluorescent detectibility to the polymer. Whenhighly fluorescent groups are employed, the fluorescent derivatizingagent may be required in amounts as low as 0.01 weight percent based ontotal weight of the polymer, and generally an amount of about 1 weightpercent based on total weight of polymer should be sufficient. While themaximum amount of fluorescent groups that may be incorporated into thepolymer is limited only by the reactive sites available for a givenpolymer, there is generally no practical purpose for excessively tagginga polymer.

Since it is believed that the derivatization reaction does not, underthe preferred and advantageous reaction conditions of the invention,proceed to the exhaustion of all fluorescent derivatizing agent and theexhaustion of all reactive sites on the polymer, it is preferred toemploy a polymer having more reactive sites (pendant groups of theFormula I) than required for exhaustion of the fluorescent derivatizingagent used. Hence while a 1 to 1 mole ratio of polymer reactive sites tofluorescent derivatizing agent is possible, and in fact less polymerreactive sites could reasonably be employed, it is desirable to have anexcess of polymer reactive sites, and a soluble polymer of anysignificant molecule weight will have such an excess generally.

In preferred embodiment, the starting material polymers of the presentinvention are water soluble polymers having molecular weights of fromabout 2,000 to about 100,000, and more preferably to about 50,000. Infurther preferred embodiment, the starting material polymers of thepresent invention are water soluble polymers having at least 10 molepercent, and more preferably at least 30 or 50 mole percent, of merunits of the Formula II. In ever more preferred embodiment, suchpolymers have at least 70 mole percent of mer units of the Formula II.Nonetheless the (trans)amidation reaction of the present invention isbelieved to proceed with as little as about 1 weight percent of such merunits, particularly if excess derivatizing agent is used.

In another preferred embodiment, the starting material polymers of thepresent invention are employed in the form of latices or emulsions,rather than aqueous solutions. Some polymers are manufactured in latexform, and for such polymers it is highly advantageous to utilize them inthat form. High molecular weight polymers are often manufactured aswater-in-oil latices, and this manufacturing technique is advantageousfor polymers of such high molecular weight that solution polymerizationis not practical. Lower molecular weight polymers could also be made inwater-in-oil form, but generally there is no practical reason foremploying this technique, which is more expensive generally thansolution polymerization. Thus while there is no theoretical minimummolecular weight for a polymer employed in the present invention inlatex form, in preferred embodiment such polymer has a molecular weightof at least 200,000, and more preferably at least 500,000, and even morepreferably at least 1,000,000.

The fluorescent group(s) of the organic derivatizing agent in preferredembodiment contains an aromatic ring system, including polynucleararomatic ring systems, which may also contain various functional groups.The molecule containing such aromatic ring system must also contain anamine radical, preferably a primary amine radical, which amine radicalmay or may not be directly substituted to the aromatic ring system.Other various functional groups that may be present in such molecule arecarboxylic acid, sulfonic acid, hydroxyl, nitrile, keto, amine,substituted amine, and the like and such functional groups may or maynot be directly substituted to the aromatic ring system. An extremelyimportant advantage of the present invention is the number and varietyof such organic fluorescent amine-containing compositions that arecommercially available as water soluble compositions, and others thatmay become water soluble, or more water soluble, upon formation of thesalts thereof. The fluorescent derivatizing agents useful for thepresent invention are available with fluorescent spectralcharacteristics that can distinguish one agent from the others. Thus aplurality of polymers may be each tagged with a different fluorescentgroup so as to be able to distinguish between such polymers by virtue oftheir resultant unique spectral characteristics.

In a preferred embodiment, with reference to Formula III above, theorganic fluorescent derivatizing agent may be defined as one in whichone of R₅ and R₆ is hydrogen and the other of R₅ and R₆ is an(alkylene)aromatic ring system in which the aromatic ring system maycontain other substituents, particularly sulfonic acid, carboxylic acidand salts thereof and the aromatic ring system may be a polynucleararomatic ring system. By (alkylene)aromatic ring system is meant thatthe aromatic ring system may be either bonded to irs amide nitrogenthrough a carbon within the ring system or bonded to such nitrogenthrough an alkylene group or a combination of an alkylene group and afunctional group, for instance when the (alkylene)aromatic ring systemis an N-alkylene substituted aromatic amide.

The amine group of the organic fluorescent derivatizing agent may becovalently bonded directly to the agent's aromatic ring system, or itmay be bonded to the ring system through an alkyl group: In other words,the group bonded to the ring system may be an amine, an aminesubstituted alkyl group; or an amine substituted alkyl group containingfurther substitution. In one preferred embodiment of the invention, theamine-containing fluorescent derivatizing agent is one containing analkyl amine, and is so preferred because the (trans)amidation reactionproceeds efficiently with such an agent. In a different preferredembodiment of the invention, the amine-containing fluorescentderivatizing agent is one containing a primary amine covalently bondedto the ring system, and is so preferred because such agents aregenerally readily available at very low cost.

A very useful group of organic fluorescent derivatizing agents contain anaphthalene ring system, which ring system is substituted with at leastone primary amine and at least one sulfonic acid group. There are manycompositions within this group that are commercially available atreasonable cost, and there are many compositions within this group,distinguished from one another by the number of amine and sulfonic acidsubstituents and, for a given number of each substituent, by theposition of each substituent on the naphthalene ring system. Below inTable I is a list of commercially available compositions within thisgroup, identified as to number of substituents and ring positions, whichlist is not meant to be exhaustive of the compositions within thisgroup.

                                      TABLE I                                     __________________________________________________________________________    Composition                                                                          Substituent at Specified Ring Position                                 Designation                                                                          1    2    3    4    5    6    7    8                                   __________________________________________________________________________    a      --NH.sub.2                                                                         --SO.sub.3 H                                                                       --   --   --   --   --   --                                  b      --NH.sub.2                                                                         --   --   --SO.sub.3 H                                                                       --   --   --                                       c      --NH.sub.2                                                                         --   --   --   --SO.sub.3 H                                                                       --   --   --                                  d      --NH.sub.2                                                                         --   --   --   --   --SO.sub.3 H                                                                       --   --                                  e      --NH.sub.2                                                                         --   --   --   --   --   --SO.sub.3 H                                                                       --                                  f      --NH.sub.2                                                                         --   --   --   --   --   --   --SO.sub.3 H                        g      --SO.sub.3 H                                                                       --NH.sub.2                                                                         --   --   --   --   --   --                                  h      --   --NH.sub.2                                                                         --   --   --SO.sub.3 H                                                                       --   --   --                                  i      --   --NH.sub.2                                                                         --   --   --   --SO.sub.3 H                                                                       --   --                                  j      --   --NH.sub.2                                                                         --   --   --   --   --SO.sub.3 H                                                                       --                                  k      --   --NH.sub.2                                                                         --   --   --   --   --   --SO.sub.3 H                        l      --SO.sub.3 H                                                                       --NH.sub.2                                                                         --   --   --SO.sub.3 H                                                                       --   --   --                                  m      --   --NH.sub.2                                                                         --   --SO.sub.3 H                                                                       --   --   --   --SO.sub.3 H                        n      --   --NH.sub.2                                                                         --   --   --SO.sub.3 H                                                                       --   --SO.sub.3 H                                                                       --                                  o      --   --NH.sub.2                                                                         --   --   --   --SO.sub.3 H                                                                       --   --SO.sub.3 H                        p      --   --NH.sub.2                                                                         --SO.sub.3 H                                                                       --   --   --SO.sub.3 H                                                                       --   --                                  q      --NH.sub.2                                                                         --   --   --SO.sub.3 H                                                                       --   --   --   --SO.sub.3 H                        r      --NH.sub.2                                                                         --   --SO.sub.3 H                                                                       --   --   --   --   --SO.sub.3 H                        s      --NH.sub.2                                                                         --   --   --SO.sub.3 H                                                                       --   --   --SO.sub.3 H                                                                       --                                  t      --NH.sub.2                                                                         --   --SO.sub.3 H                                                                       --   --   --   --SO.sub.3 H                                                                       --                                  u      --NH.sub.2                                                                         --   --SO.sub.3 H                                                                       --   --   --SO.sub.3 H                                                                       --   --                                  v      --NH.sub.2                                                                         --   --SO.sub.3 H                                                                       --   --   --SO.sub.3 H                                                                       --   --SO.sub.3 H                        w      --NH.sub.2                                                                         --   --   --SO.sub.3 H                                                                       --   --SO.sub.3 H                                                                       --   --SO.sub.3 H                        x      --   --NH.sub.2                                                                         --   --SO.sub.3 H                                                                       --   --SO.sub.3 H                                                                       --   --SO.sub.3 H                        y      --SO.sub.3 H                                                                       --NH.sub.2                                                                         --   --   --SO.sub.3 H                                                                       --   --SO.sub.3 H                                                                       --                                  aa     --   --NH.sub.2                                                                         --SO.sub.3 H                                                                       --   --   --SO.sub.3 H                                                                       --   --SO.sub.3 H                        __________________________________________________________________________

The amine-containing naphthalene compositions set forth in Table I aboveinclude amino naphthalene monosulfonic acids (Compositions a through k),amino naphthalene disulfonic acids (Compositions l through u), and aminonaphthalene trisulfonic acids (Compositions v through aa), and variousof these compositions are supplied as, or are available as, their sodiumand/or potassium salt(s).

There are numerous commercially available products that contain afluorescent group and either a primary or secondary amine, or aplurality of same. For instance, Aldrich Chemical Company, Inc., listsin excess of 50 of such products in addition to naphthalene derivatives.Such compositions are generally dyes or dye intermediates, and includesome compositions that do not have a polynuclear aromatic ring system,such as benzene derivatives and compositions containing a plurality ofbenzene rings. Again the amine group required for the present inventionmay be a primary amine covalently bonded directly to the aromatic ringor it may be a secondary amine bonded to the aromatic ring, or it may bebonded to another group in turn bonded to the aromatic ring.

There is no need generally for the trans)amidation reaction to proceedto extent where all of the organic fluorescent derivatizing agent isincorporated into the polymer. Residual fluorescent derivatizing agentis generally innocuous, and when desired may be separated from theproduct polymer, such as by selective precipitation of the polymer fromthe liquid system employed in the (trans)amidation reaction.

In preferred embodiment, the product polymer has different spectralproperties than the organic fluorescent derivatizing agent, and hencethe presence of product polymer successfully tagged by the(trans)amidation reaction can be determined merely by the presence ofits particular major fluorescent peak(s).

The following Examples 1 through 37 demonstrate the advantages of thepresent invention, including without limitation the successfulfluorescent tagging of pre-existing polymers without any deleteriouseffect on the polymer of any significance, using a wide variety ofamine-containing fluorescent derivatizing agents, The derivatizingagents used were all commercially available, and many of such agents arecommercially available at low cost. In some instances, noted in moredetail below, the fluorescent spectras of the derivatized polymersdiffer from the fluorescent spectras of the derivatizing agents used,and hence one may confirm that fluorescent groups have been incorporatedinto the polymer by fluorescent spectral analysis without isolating theproduct polymer from any residual derivatizing agent that may bepresent. The synthesis method is exemplied using reaction mixturescontaining high concentrations of polymer starting material, moderate pHconditions, a single reaction step, and generally low levels ofderivatizing agent. The synthesis method proceeds successfully in shorttime periods. The polymers employed vary as to the amount of pendantgroups of Formula I, and a number of the polymers employed have diversependant groups outside of Formula I. Exemplified are derivatizationsusing a single type of pendant group within Formula I, that is, anacrylic acid homopolymer, and a number of polymers containing both(meth)acrylic acid and acrylamide units.

The polymers employed as starting material polymers in Examples 1 to 37each have more than 70 mole percent of mer units within Formula II andweight average molecular weights of less than 100,000. The followingabbreviations are used for the polymer units of these and otherexamples:

    ______________________________________                                        AA              Acrylic acid                                                  AcAm            Acrylamide                                                    SMA             Sulfomethylacrylamide                                         VA              Vinyl acetate                                                 MAA             Methacrylic acid                                              ACN             Acrylonitrile                                                 ______________________________________                                    

It has been found that the (trans)amidation derivatization of thepresent invention may proceed together with other post-polymerizationderivatization reactions that are feasible under the reactionconditions. For instance, in Examples 9, 10, 13, 20, and 22 to 32, asulfomethylation derivatization reaction is conducted simultaneouslyusing a formaldehyde-bisulfite (HOCH₂ SO₃ Na) derivatizing agent.

In a number of the synthesis examples that follow, sodium hydroxide isadded to the reaction mixture for the purpose of neutralizing thefluorescent derivatizing agent by forming the salt form, which is morewater soluble.

EXAMPLE 1

20.76 g. of L-tryptophan was admixed into 115 g. of an aqueous solutioncontaining 36.22 g. of an AA/AcAm copolymer (20 mole percent ofL-tryptophan based on the total moles of mer units, both AA and AcAm, inthe polymer). This admixture was placed into a 300 ml. Parr reactor andtherein heated to 150° C. At this temperature the pressure within theParr reactor was about 65 psi. The admixture was held therein at 150° C.for four hours, and then cooled to room temperature and removed from thereactor. The polymer product of this reaction was determined to have aweight average molecule weight of 11,700 and a polydispersity (weightaverage molecular weight/number average molecular weight) of 3.3, basedon polystyrene sulfonate standards. Size Exclusion Chromatography with0.03M sodium nitrate-phosphate buffer as the mobile phase was employedfor residual L-tryptophan analysis. Since L-tryptophan fluoresces, afluorescence detector was employed to monitor the elutents. Thefluorescence monitoring was conducted at a wavelength of excitation of280 nanometers and at a wavelength of emission of 370 nanometers, whichidentification of wavelengths can be expressed as "ex 280 nm" and "em370 nm", a format used at times herein. It was determined that 24 weightpercent of the L-tryptophan charged remained as residual, representing a76 wt. percent incorporation into the polymer assuming no degradation ofthe L-tryptophan occurred. Thus about 15 mole percent of the mer unitshad been tagged, and it was determined by GPC analysis that theL-tryptophan tags had been incorporated into the polymer throughout itsmolecular weight range. This polymer could be detected with afluorescence detector at concentrations as low as one ppm polymer inwater without any difficulty.

In the following Examples 2 through 32 and 35 through 37, wherein about140 to about 150 grams of aqueous solution of starting material polymerwas employed, the reaction vessel used was also a 300 m. Parr reactor.

EXAMPLE 2

To 150 grams of an aqueous solution containing about 55 grams of anAA/AcAm/SMA terpolymer was added 1.11 grams (2 wt. percent based onpolymer weight) of 1-[(2-aminoethyl)amino]naphthalene-5-sulfonic acid,as the sodium salt (having a formula weight of 288). This admixture wasplaced in a Parr reactor, purged with nitrogen, and then heated to 150°C., and held at this temperature for 5 hours, and then cooled to roomtemperature and removed from the reactor. The polymer product wasdetermined to have a weight average molecular weight of 15,500 and apolydispersity of 2.1, based on polyethylene glycol standards. Themolecular weight of this polymer product was about the same as thestarting material polymer. Based on size exclusion chromatography, thefluorescent intensity of this polymer was about 62 times that of thestarting material polymer, the pendant fluorescent groups appeared to beuniformly distributed on the polymer and only a very small peak fromresidual fluorescent derivatizing agent was observed at very longelution times.

EXAMPLE 3

The same procedure as described in Example 2 above was repeated exceptthat the amine-containing fluorescent derivatizing agent was1-naphthylmethyl) amine, which was also used in the amount of 1.11 gramsor 2 weight percent based on total polymer weight. The polymer productweight average molecular weight was determined to be 14,400 which wasabout the same as the starting material polymer, within experimentalerror. The fluorescent intensity of this polymer product was about 66times that of the starting material polymer and the pendant fluorescentgroups appeared to be uniformly distributed on the polymer.

EXAMPLES 4 TO 8

The same procedure as described in Examples 2 and 3 above was repeatedexcept that different amine-containing fluorescent derivatizing agentswere employed, and these were all employed as in Examples 2 and 3, thatis, in the amount of 1.11 grams or 2 weight percent based on totalpolymer weight. The resultant polymer product reaction mixture in eachinstance contained some residual derivatizing agent. The derivatizingagents employed and the characterization of the polymer products are setforth below in Table II.

                                      TABLE II                                    __________________________________________________________________________                     Polymer Product                                                   Derivatizing                                                                              Wt. Average     Fluorescent                                  Example                                                                            Agent       Molecular Wt.                                                                          Polydispersity                                                                       Intensity                                    __________________________________________________________________________    4    1-amino-5-naphthalene                                                                     17,100   1.8    20                                                sulfonic acid                                                            5    1-amino-5-naphthalene                                                                     16,100   1.9    6.5                                               sulfonic acid                                                            6    2-amino-4,8-naphthalene                                                                   15,800   2.1    7.7                                               disulfonic acid                                                               (disodium salt)                                                          7    1-amino-7-naphthalene                                                                     15,700   1.9    19.8                                              sulfonic acid                                                            8    1-amino-4-naphthalene                                                                     15,600   2.1    19.6                                              sulfonic acid                                                            __________________________________________________________________________

EXAMPLES 9 AND 10

In each of these Examples 9 and 10, to 145 grams of an aqueous solutioncontaining 50.75 grams of an AA/AcAm copolymer was added 20.35 grams ofHOCH₂ SO₃ Na (20 mole percent based on total moles of mer units in totalstarting material polymer) and 1.22 grams of 1-amino-5-naphthalenesulfonic acid, as the acid, (having a formula weight of 223.25). Theseadmixtures were each placed in a Parr reactor, purged with nitrogen, andthen heated to an elevated temperature, and held at that elevatedtemperature for 5 hours. In Example 9 such elevated temperature was 150°C., and in Example 10 it was 137° C. After such period of heating, thereaction mixtures were cooled to room temperature and removed from thereactor. In each of Examples 9 and 10 the polymer product had apolydispersity of 1.9 and similar weight average molecular weights,i.e., respectively 18,800 and 18,900. The fluorescent intensities ofthese polymer products were respectively 54.2 and 60.6 times greaterthan the starting material polymer. Residual fluorescent derivatizingagent was present in the reaction mixtures to a minor extent.

The above Examples 9 and 10 exemplify the conducting of a secondpost-polymerization derivatization, adding pendant groups useful forscale inhibiting applications, simultaneously with the (trans)amidationreaction to incorporate the fluorescent derivatizing agent into thepolymer. More particularly, the formaldehyde-bisulfite employed in thereaction provides sulfomethylation derivatization to polymer pendantgroups of Formula I above wherein R is --OR' and has been shown toproceed under reaction conditions of the (trans)amidation reaction. Inpreferred embodiment, at least one mole of the formaldehyde-bisulfite isused per 100 moles of mer units in the starting material polymer, and inmore preferred embodiment at least 5 mole percent formaldehyde-bisulfiteis employed based on total polymer mer units. In further preferredembodiments, the starting material polymer is an acrylic acid polymer orcopolymer with acrylamide, and is a polymer having a weight averagemolecular weight of from about 2,000 to about 200,000, or at least toabout 50,000 to 100,000.

EXAMPLE 11

To 150 grams of an aqueous solution containing about 48.75 grams of anacrylic acid homopolymer was added 0.98 grams (about 2 wt. percent basedon polymer weight) of 1-amino-5-naphthalene sulfonic acid, as the acid,(having a formula weight of 223.25). This admixture was placed in a Parrreactor, purged with nitrogen, and then heating to 150° C. for 5 hours,and then cooled to room temperature and removed from the reactor. Thepolymer product was determined to have a weight average molecular weightof 5,100 (as compared to about 4,500 for the starting material polymer)and a polydispersity of 1.5. The fluorescent intensity of this polymerproduct was about 366 times that the starting material polymer, and thependant fluorescent groups appeared to be uniformly distributed on thepolymer. Some residual derivatizing agent was observed in the gelpermeation chromatograms.

EXAMPLE 12

The same procedure as described in Examples 2, 3 and 4 to 8 above wasrepeated (all of which, including the present example, employed anAA/AcAm/SMA starting material polymer) except that the fluorescentderivatizing agent employed was the 2-amino-1-naphthalene sulfonic acid,as the acid, and this was employed in the amount of 1.11 grams or 2weight percent based on total polymer.

EXAMPLE 13

The procedure described in Example 10 above was repeated except that theamine-containing fluorescent derivatizing agent employed was thedisodium salt of 1-amino-3,6,8-naphthalene trisulfonate (anhydrousformula weight of 427.34). The amount of this derivatizing agentemployed was 1.22 grams.

EXAMPLE 14

To 150 grams of an aqueous solution containing about 52.5 grams of anAA/AcAm/VA terpolymer was added 1.05 grams (2 wt. percent based onpolymer weight) of 1-amino-5-naphthalene sulfonic acid, as the acid,(having a formula weight of 233.25). This admixture was placed in a Parrreactor, purged with nitrogen, and then heated to 150° C., and held atthis temperature for 5 hours, and then cooled to room temperature andremoved from the reactor. The reaction mixture was a clear tan colorhaving a pH of 4.6. The polymer was determined to be 58 mole percentanionic at pH of 10 by titration.

EXAMPLES 15 and 16

Example 14 was repeated except that different starting material polymerswere used. Example 15's starting material polymer was an AA/AcAm/MAAterpolymer and Example 16's starting material polymer was an AA/AcAm/ACNterpolymer. The reaction mixtures (after reaction) were respectively aturbid brown solution with solid material settled at the bottom and aclear brown solution, and respectively had pH's of 4.5 and 4.6. Example15's product polymer was determined to be 56 mole percent anionic at pHof 10 by titration. Example 16's product polymer was determined to be 65mole percent at pH 10 by titration.

EXAMPLES 17 to 19

In each of these Examples 17 to 19, to 150 grams of an aqueous solutioncontaining 52.5 grams of a starting material polymer (described below)was added 1.05 grams (2 wt. percent based on polymer weight) of1-amino-7-naphthalene sulfonic acid, as the acid, (having a formulaweight of 223.25). These admixtures were each placed in a Parr reactor,purged with nitrogen, and then heated to 150° C., and held at thistemperature for 5 hours, and then cooled to room temperature and removedfrom the reactor. The starting material polymers and some productcharacteristics are set forth below in Table III.

                                      TABLE III                                   __________________________________________________________________________                                  Polymer Product                                                               Mole % Anionic                                  Starting Material Polymer                                                                       Reaction Mixture                                                                          at pH 10                                        Example                                                                            Monomer Units                                                                              pH                                                                              Visual Appearance                                                                       (by titration)                                  __________________________________________________________________________    17   AA/AcAm/ACN  4.6                                                                             clear brown soln.                                                                       62                                              18   AA/AcAm/VA   4.6                                                                             clear yellow soln.                                                                      58                                              19   AA/AcAm/MAA  4.5                                                                             turbid yellow soln.                                                                     56                                              __________________________________________________________________________

EXAMPLE 20

The procedure described in Example 10 above was repeated except that theamine-containing fluorescent derivatizing agent employed was the1-amino-7-napthalene sulfonic acid employed as the acid, (formula weightof 223.25) and the amount of this derivatizing agent employed was 1.22grams.

EXAMPLE 21

The procedure described in Examples 17 to 19 above was repeated exceptan AA/AcAm/SMA terpolymer was used as the starting material polymer.This terpolymer is like that used in Examples 2 to 8 and 12 above exceptthat the pH of the aqueous polymer solution was about 11.

EXAMPLES 22 to 24

In each of these Examples 22, 23 and 24, to 145 grams of an aqueoussolution containing 50.75 grams of an AA/AcAm copolymer was added 20.35grams of HOCH₂ SO₃ Na (20 mole percent based on total moles of mer unitsin total starting material polymer) and 1.22 grams of1-amino-3,6,8-naphthalene trisulfonic acid as the disodium salt(monoacid having an undetermined amount of water of hydration and ananhydrous formula weight of 427.34). The starting material polymers ofeach of these Examples were prepared in different polymerizationbatches. Each admixture was placed in Parr reactors, purged withnitrogen, heated to 137° C. and held at such elevated temperature for aperiod of 5 hours.

EXAMPLE 25

The procedure of Examples 22 to 24 above was repeated except thatinstead of the trisulfonic acid fluorescent derivatizing agent, 1.22grams of 1-amino-7-naphthalene sulfonic acid was used. The productreaction mixture was a bright yellow solution having a pH of 5.0.

EXAMPLES 26 to 28

The procedures of Examples 22 to 24 above was repeated except that ineach of these Examples 26 to 28 a different fluorescent derivatizingagent was used and sodium hydroxide was added to each reaction mixture.The 50.75 grams of AA/AcAm copolymer starting material represents 0.710moles of polymer mer units. In each of these Examples the amount offluorescent derivatizing agent employed represented 0.005 moles, or 0.7mole percent based on total moles of mer units, and 0.44 grams of 50percent NaOH (0.005 moles) was added to each reaction mixture. Theidentities of the derivatizing agents used and the characterizations ofthe product reaction mixtures are set forth below in Table IV.

                                      TABLE IV                                    __________________________________________________________________________                                   Product Reaction Mixture                                       Product Polymer                                                                              Wt.                                                            Mole Percent of                                                                              Percent                                        Example                                                                            Derivatizing Agent                                                                       --CONH.sub.2                                                                        --CO.sub.2                                                                        --SO.sub.3 --                                                                      Polymer                                                                            Appearance                                __________________________________________________________________________    26   2-amino-1-naphthalene                                                                    26    56  18   37.6 very turbid                                    sulfonic acid                                                            27   2-amino-6-naphthalene                                                                    27    55  18   37.6 contains insoluble                             sulfonic acid                  solids                                    28   2-amino-8-naphthalene                                                                    29    53  17   36.9 slightly turbid                                sulfonic acid                                                            __________________________________________________________________________

EXAMPLES 29 to 32

The procedure of Examples 22 to 24 above was repeated except that ineach of these Examples 29 to 32 a different fluorescent derivatizingagent was used and sodium hydroxide was added to each reaction mixture.The 50.75 grams of AA/AcAm copolymer starting material represents 0.710mole of polymer mer units. In each of these examples the amount offluorescent derivatizing agent employed represented 0.004 moles, orabout 0.56 mole percent based on total moles of mer units, and 0.28grams of 50 percent NaOH (0.004 moles) was added to each reactionmixture. The identities of the derivatizing agents used and thecharacterizations of the product reaction mixtures are set forth belowin Table V.

                                      TABLE V                                     __________________________________________________________________________                                    Product Reaction Mixture                                       Product Polymer                                                                              Wt.                                                            Mole Percent of                                                                              Percent                                       Example                                                                            Derivatizing Agent                                                                        --CONH.sub.2                                                                        --CO.sub.2                                                                        --SO.sub.3 --                                                                      Polymer                                                                            Appearance                               __________________________________________________________________________    29   2-amino-4,8-naphthalene                                                                   27    55  18   37.7 slightly turbid                               disulfonic acid disodium                                                      salt                                                                     30   2-amino-1,3-naphthalene                                                                   22    60  18   37.7 slightly turbid                               disulfonic acid disodium                                                      salt                                                                     31   2-amino-6,8-naphthalene                                                                   26    57  17   31.2 moderately turbid                             disulfonic acid mono-                                                         potassium salt                                                           32   2-amino-3,6-naphthalene                                                                   26    57  17   37.3 very turbid                                   disulfonic acid mono-                                                         sodium salt (trihydrate)                                                 __________________________________________________________________________

EXAMPLE 33

A (trans)amidation reaction was conducted in a 10 ml. reactivial at 80°C., using a solution of an acrylic acid/acrylamide/sulfomethylacrylamideterpolymer, diluted to 10,weight percent polymer solids, buffered to pHof 5 with 0.1M phosphate buffer, to which was added 1 weight percentbased on polymer solids of the amine-containing fluorescent derivatizingagent. The derivatizing agent used was Cresyl Violet Acetate which iscommercially available from the Aldrich Chemical Company, Inc. Thepolymer product was recovered and purified by double precipitation inacetone, filtering the polymer/acetone mixture through acetone-washedmillipore filter (type N, 0.45 μm nylon membrane filters), and thensubjected to gel permeation chromatography with fluorescence detection.The product polymer was determined to have a major light absorption peakat a wavelength of 584 nm and a major fluorescent emission peak at awavelength of 613 nm and contained about 0.046 weight percent of thefluorescent group.

EXAMPLE 34

The procedure of Example 33 was repeated except that the polymerstarting material was an AA/AcAm copolymer and the fluorescentderivatizing agent was Brilliant Acid Yellow 8G from Pylam Dyes. Theproduct polymer was determined to have a major light absorption peak ata wavelength of 420 and a major fluorescent emission peak at awavelength of 510. The amount of fluorescent group incorporated into thepolymer was undetermined.

EXAMPLES 35 to 37

A (trans)amidation reaction was conducted using an AA/AcAm/SMAterpolymer starting material and in each example a different fluorescentderivatizing agent, described below. In each Example 150 grams of anaqueous solution containing 55.5 grams of the starting material polymerwas used. In Examples 35 and 36 the polymer solutions were buffered topH of 7 with 0.1M phosphate buffer. In Example 37 the polymer solutionwas buffered to pH of 9 in the same manner. The derivatizing agentemployed was added to the polymer solution and the reaction conducted ina 300 mll.Parr reactor at 150° C. for a 5 hour period in each Example.The derivatizing agents used were respectively L-tryptophan in Example35, tryptamine in example 36, and Fluoresceinamine (available fromAldrich Chemical Company) in Example 37. The product polymers wereisolated and purified as described above in Examples 33 and 34. Theamount of the derivatizing agent used, the major absorption and emissionpeaks of the polymer products, and the approximate weight percent of thefluorescent group contained in the polymer product, as set forth belowin Table VI:

                                      TABLE VI                                    __________________________________________________________________________          Wt. % Derivatizing                                                                       Absorption                                                                            Emission                                                                              Wt. %                                              Agent based on                                                                           Peak Wave-                                                                            Peak Wave-                                                                            Fluorescent                                  Example                                                                             Polymer Solids                                                                           length (nm)                                                                           length (nm)                                                                           Group                                        __________________________________________________________________________    37    10         265     350     0.59                                         38    5          272     351     1.83                                         39    5          488     524     0.71                                         __________________________________________________________________________

As seen from the forgoing, polymers prepared by the (trans)amidation ofa polymer having mer units of Formula I above, using as the(trans)amidation derivatizing agent an organic fluorescent compositionof Formula III above, may be defined by the structural formula ofFormula V below: ##STR5## wherein R₁, R₂, R₃ and R₄ are as defined abovefor Formula II, and R₅ and R₆ are as defined above for Formula III. Inpreferred embodiment the present invention is also directed to polymershaving mer units of Formula V wherein one of R₅ and R₆ is hydrogen andthe other is an (alkylene)naphthalene which may be further substitutedon the naphthalene ring with one or more sulfonic acid groups or saltsthereof. By "(alkylene)naphthalene" is meant herein both a naphthalenegroup directly bonded to the nitrogen of Formula V or a naphthlenebonded to the nitrogen through an alkylene or partially alkylene group,or the alkylene group, or partial alkylene group, is bonded to thenaphthalene ring through a functional group.

In preferred embodiment the derivatizing agents are selected from thosethat a reasonably high "relative performance" for a given background. Asnoted above, a molecule is generally considered highly fluorescent whenit has a fluorescent quantum efficiency, or fluorescent quantum yield,within the range of from about 0.1 to about 1.0, and a light absorbancemolar extinction coefficient of at least 1,000. The magnitude offluorescent signal, or relative fluorescence, is the product of thefluorescent quantum yield multiplied times the light absorbance molarextinction coefficient. Thus for instance if two compositions each hadthe minimal 1,000 light absorbance molar extinction coefficient, but onehad a fluorescent quantum yield of 0.1 and the other had a fluorescentquantum yield of almost 1.0, the latter would have a ten-fold higherrelative fluorescence. For a given application, however, that featurealone would not render the latter derivatizing agent the better choice,because the relative fluorescence determination does not take intoconsideration any fluorescent background characteristics of the medium(either natural or added by the system process) in which the taggedpolymer is to be used, generally referred to as background fluorescence.The "relative performance", as this phrase is used herein, is the ratioof the relative fluorescence of a composition to the relativefluorescence of a given background medium. The fluorescence readings aretypically measured at the excitation/emission wavelengths that representmajor peaks for the given fluorescent tagged polymer. For a givenprocess sample background, two compounds having similar relativefluorescence values, but at different excitation and/or emissionwavelengths, may have diverse relative performance values because theirrelative performances are being measured at different wavelengths andthe fluorescent intensity of the background at these diverse wavelengthsmay be significantly different. Some generalities may be considered.Industrial cooling waters generally have an overall higher fluorescentintensity than industrial boiler waters, and therefore a degree ofpolymer tagging that is reasonably high for use in boiler waters may notbe sufficiently high for cooling waters, since of course the intensityof fluorescence must not be overwhelmed by the background fluorescenceand the intensity of fluorescence is dependent on the concentrationlevel of the fluorescent species. Similarly, a polymer that is to beused at high concentration levels in a given background medium need notbe tagged to the same extent as one that is to be used at much lowerconcentration levels, other parameters being the same. Further, aderivatizing agent that is satisfactory for use in one type ofbackground medium, for instance cooling waters, may not be suitable fortagging polymers that are to be used in a different medium, for instancewaste water, because that agent's major excitation/emission peaks maysubstantially coincide with the background fluorescence peaks of thewaste water and hence have a low relative performance value for such abackground.

As noted above, the amino-naphthalene sulfonic acid derivatizing agentsgenerally have different major fluorescent peaks than the productpolymer tagged with such agent. While this spectral shift is obviouslyhighly advantageous for determining the success of a derivatizationand/or presence of residual agent, it of course renders the relativeperformance of the agent for a given background somewhat different thanthe relative performance of a polymer tagged with such agent becausesuch relative performances are being measured in somewhat differentspectral areas. Nonetheless this shift and its impact on relativeperformances is, for the purposes of using the agents per se in relativeperformance determinations against a given background, a minor effectthat does not diminish the value of such determinations, particularlysince the use of the fluorescence spectral data of the derivatizingagents in a given background permits a large number of agents to bescreened without the burden of conducting a large number of derivatizingreactions.

Thus in Example 38 below a survey of relative performance values of anumber of fluorescent derivatizing agents against a cooling waterbackground is given as representative of the use of such screeningmethod for any other group of derivatizing agents and any other type ofbackground.

EXAMPLE 38

The relative performances of a variety of fluorescent derivatizingagents were surveyed against a cooling water background as follows. Anaqueous solution of each agent at a concentration level of 0.4 ppm (acidactives) and the fluorescent intensity of each agent at its fluorescencemaximum was determined, in comparison to a fluorescence referencestandard. The standard used was 1,5-naphthalene disulfonic acid, whichis not a derivatizing agent for the purposes of the present inventionbecause it has no amine functionality. This standard was also measuredat its fluorescence maximum in an aqueous solution at a concentration of0.4 ppm (acid actives) and its intensity was assigned a "relativeintensity value" of 100%. The "relative intensity values" of each of theother compositions tested were assigned in relationship to the intensityof the standard. For instance, a composition that had twice theintensity of the standard (the standard and the composition each beingmeasured at their own fluorescence maximums) would be given a relativeintensity value of 200%. Then the relative intensity values of thevarious compositions were compared to that of the cooling waterbackground at the fluorescent maximum (peak excitation/emissionwavelengths) of the composition. The cooling water fluorescent intensityemployed was the average relative intensity of ten representativecooling water formulations measured for combination of wavelengths ofexcitation and emission within the range required for this survey. Therelative performance for each composition thus is the value determinedby dividing the relative intensity value determined for the fluorescenceof each composition by the relative intensity value of the backgroundfluorescence of cooling water at the same combination of wavelengths.The identities of the various compositions surveyed and the valuesdetermined are set forth below in Table VII.

                  TABLE VII                                                       ______________________________________                                                                 Relative                                                            Fluorescent                                                                             Intensity  Rel-                                                     Maximum   Values (%) ative                                                    ("nm")    Composition/                                                                             Per-                                      Composition    ex/em     Background formance                                  ______________________________________                                        1,5-naphthalene disulfonic                                                                   290/330   100/7.2    14                                        acid (the standard)                                                           1-amino-4-naphthalene                                                                        325/420   444/18.5   24                                        sulfonic acid                                                                 1-amino-5-naphthalene                                                                        240/480    14/34.8   0                                         sulfonic acid                                                                 1-amino-6-naphthalene                                                                        245/485    74/22.7   3                                         sulfonic acid                                                                 1-amino-7-naphthalene                                                                        340/480    80/11.0   7                                         sulfonic acid                                                                 1-amino-8-naphthalene                                                                        --         0/--      0                                         sulfonic acid                                                                 2-amino-1-naphthalene                                                                        245/485   150/22.7   7                                         sulfonic acid                                                                 2-amino-5-naphthalene                                                                        245/440   750/9.2    82                                        sulfonic acid                                                                 2-amino-6-naphthalene                                                                        245/420   760/9.7    78                                        sulfonic acid                                                                 2-amino-7-naphthalene                                                                        245/440   446/9.2    48                                        sulfonic acid                                                                 2-amino-8-naphthalene                                                                        240/440   638/8.5    75                                        sulfonic acid                                                                 1-amino-4,8-naphthalene                                                                      255/500   122/26.2   5                                         disulfonic acid                                                               1-amino-3,8-naphthalene                                                                      245/480   540/21.6   25                                        disulfonic acid                                                               2-amino-1,5-naphthalene                                                                      250/420   486/10.0   49                                        disulfonic acid                                                               2-amino-4,8-naphthalene                                                                      245/440   564/9.2    61                                        disulfonic acid                                                               2-amino-5,7-naphthalene                                                                      250/460   776/8.0    97                                        disulfonic acid                                                               2-amino-6,8-naphthalene                                                                      250/445   69/9.6     7                                         disulfonic acid                                                               2-amino-3,6-naphthalene                                                                      250/440   77/9.8     8                                         disulfonic acid                                                               1-amino-3,6-naphthalene                                                                      360/500    4/9.0     0                                         trisulfonic acid                                                              4-amino-benzene                                                                              250/340   26/3.2     8                                         sulfonic acid                                                                 2-amino-5-methylbenzene                                                                      240/370   19/7.2     3                                         sulfonic acid                                                                 amino-2,5-benzene                                                                            310/380    54/14.0   4                                         disulfonic acid                                                               2-amino-benzoic acid                                                                         240/400   110/8.5    13                                        3-amino-benzoic acid                                                                         240/370   21/7.2     3                                         4-amino-benzoic acid                                                                         270/340   82/6.2     13                                        aniline        230/340    4/4.7     1                                         ______________________________________                                    

From the survey results set forth in Table VII above, it is noted thatthe 1-amino-8-naphthalene sulfonic acid did not provide detectablefluorescence. Beyond such composition, the survey results provide a goodmeasure of which derivatizing agents may be preferred for taggingpolymers to be used in cooling waters. Generally a relative performancevalue of at least 5 is preferred, a relative performance value of atleast 10 is more preferred, and most preferred are those agents having arelative performance value of 15 and greater. A low performance value ona given survey, however, does not exclude a composition as a potentialderivatizing agent generally. For instance, 1-amino-6-naphthalenesulfonic acid has a relative performance value in the survey of TableVII of only 3, but its relative intensity value is 74%. In comparison,the 4-amino-benzene sulfonic acid has a higher relative performancevalue of 8 and a lower relative intensity value of 26%. Thus while1-amino-6-naphthalene sulfonic acid may not be a preferred tagging agentfor cooling water polymers, its relative intensity is sufficiently highthat it may well be a preferred agent for polymers to be used in anapplication with a different background fluorescence. In addition, thosecompositions shown to have low relative intensities may be sufficientfor use in polymers to be used in mediums having lower backgroundfluorescent intensities, and may be there the agent of choice for otherreasons, such as cost, availability, efficiency of derivatizationreaction, toxity, compatibility, or other reasons. Hence surveys asshown in Example 38 are a tool for making a reasonable selection ofderivatizing agent for a given known purpose, and not an absolutecategorization of potential usefulness of derivatizing agents in allapplications.

EXAMPLE 39

Using the polymer derivatized as described in Example 7 above as arepresentative polymer suitable for cooling water treatment, thetolerance of the polymer, as to fluorescent intensity, upon exposure tochemical species generally present in industrial cooling waters wasdetermined as follows. For each chemical species tested, an aqueoussolution of the polymer (at a concentration level of 7.5 ppm as acidactives) and a certain amount of the chemical species was prepared andmixed for one minute, after which the fluorescent intensity wasdetermined and compared to a sample of the same polymer, similarlydiluted, but not exposed to any of the chemical species. Theconcentrations of the chemical species, which are set forth in TableVIII below, were 10 times or greater than the concentrations encounteredin typical cooling waters. The results are reported as a percentage offluorescent intensity, as compared to the polymer sample not exposed toany chemical species (the blank), which of course would be rated as100%. The test results are set forth below in Table VIII. It is notedthat an interference is commonly considered a chemical species oroperating condition that produces a 10% change in the analyticalresponse. These tests were designed to detect fluorescence quenchingwhich would occur instantly, if at all. It is seen from Table VIII belowthat the various chemical species tested, except very high levels ofionic iron, do not produce an interference result even at the very highconcentration levels employed. Given these test results, it is believedthat none of the chemical species will have any significant effect onthe fluorescent intesity of the tagged polymer in typical cooling watersystems. Fluorescent intensity values that differ by 1% or less areconsidered equivalent, being within statistical error limits.

                  TABLE VIII                                                      ______________________________________                                        Chemical   Chemical Species                                                                              Fluorescent                                        Species    Concentration   Intensity (%)                                      ______________________________________                                        Ca.sup.+2  10,000 ppm (as CaCO.sub.3)                                                                    100                                                Mg.sup.+2  10,000 ppm (as CaCO.sub.3)                                                                    100                                                HCO.sub.3.sup.-                                                                          10,000 ppm (as CaCO.sub.3)                                                                    102                                                SO.sub.4.sup.-2                                                                          10,000 ppm (as SO.sub.4.sup.-2)                                                                99                                                Cl.sup.-   10,000 ppm (as Cl.sup.-)                                                                       99                                                Na.sup.+   10,000 ppm (as Na.sup.+)                                                                      102                                                Zn.sup.+2     10 ppm (as Zn.sup.+2)                                                                       97                                                Fe.sup.+2,+3                                                                                10 ppm (as Fe.sup.+2,+3)                                                                    52                                                           adjust to pH 3   96                                                           adjust to pH 10 103                                                ______________________________________                                    

In addition, a polymer such as that prepared in Example 7, tagged with asulfonate-containing derivatizing agent, is extremely tolerant, as tofluorescent intensity, to extremely high levels of bleach, a substancealso found in industrial water systems, while the derivatizing agentsthemselves are much less tolerant.

EXAMPLE 40

Using the polymers derivatized as described in Examples 4, 7 and 10above as representative of polymers suitable for cooling watertreatment, the effect of the tagging on polymer performance wasdetermined as follows. These three tagged polymers, and an underivatizedAA/AcAm/SMA terpolymer of the same composition as employed in Examples4, 7 and 10, were tested to determine their performances in a calciumphosphate threshold inhibition performance test using test conditionsdescribed in U.S. Pat. No. 4,752,443 which is hereby incorporatedhereinto by reference. The calcium phosphate inhibition results arereported in percent inhibition as described in such patent. The testresults are set forth below in Table IX.

                  TABLE IX                                                        ______________________________________                                                            % Calcium                                                 Polymer Preparation Example                                                                       Phosphate Inhibition                                      ______________________________________                                        Example 4           81                                                        Example 7           83                                                         Example 10         80                                                        underivatized AA/AcAm/SMA                                                                         85                                                        terpolymer                                                                    ______________________________________                                    

As seen from the results set forth in Table IX above, the fluorescenttagging of these polymers has not caused a detrimental response to thecalcium phosphate inhibition performance of the polymers.

The fluorescent derivatizing agents that have functionalities other thanthe aromatic ring system and the amine, for instance theamino-naphthaline mono- and disulfonic acids, have toxity levels, asreported in the literature for the LD50 test, oral administration onrats, that are favorably low, for instance in comparison to aniline(benzene amine). A sampling of such literature toxicity data is setforth below in Table X.

                  TABLE X                                                         ______________________________________                                                        Reported LD50 (oral/rats)                                                     Toxity Data                                                   Derivatizing Agent                                                                            (grams/kilogram)                                              ______________________________________                                        2-amino-1-naphthalene                                                                          19.4                                                         sulfonic acid                                                                 2-amino-6-naphthlene                                                                          >5.0                                                          sulfonic acid                                                                 2-amino-4,8-naphthalene                                                                       >5.0                                                          disulfonic acid                                                               2-amino-5,7-naphthalene                                                                        2.0                                                          disulfonic acid                                                               2-amino-6,8-naphthalene                                                                       >5.0                                                          disulfonic acid                                                               aniline           0.25                                                        ______________________________________                                    

In the following Example 41 there is given a post-polymerizationderivatization procedure suitable for polymers whose molecular weightsare too high to be used as a water solution. The polymer startingmaterial is of the type commercially available in the form of awater-in-oil emulsion or latex and the polymer is useful for industrialwaste water treatment.

EXAMPLE 41

170.0 grams of a water-in-oil latex which contained 51.85 grams of apolymer was admixed with 5.05 grams of additional surfactant, a solutionof taurine (2-aminoethanesulfonic acid) and a solution of2-amino-8-naphthalene sulfonic acid, to form the reaction mixture. Thepolymer was a homopolymer of acrylamide having a weight averagemolecular weight of about 10,000,000 (a reduced specific viscosity ofabout 20). The polymer was formed in such water-in-oil latex form andsuch latex contains about 2 weight percent surfactant based on totallatex. The additional surfactant employed was a nonionic surfactantcommercially available from ICI Americas, Inc. under the tradename ofSpan 80 (Span is a registered trademark of ICI Americas, Inc.). Thetaurine solution was comprised of 9.12 grams taurine, 5.83 grams of 50%NaOH, and 1.63 grams of deionized water. The solution of2-amino-8-naphthalene sulfonic acid was comprised of 1.04 g.2-amino-8-naphthalene sulfonic acid, 0.37 grams of 50% NaOH, and 8.99grams of deionized water. The taurine solution was heated to dissolvethe taurine and added slowly to the latex (with the additionalsurfactant) while stirring, and then the 2-amino-8-naphthalene sulfonicacid solution was added slowly while likewise stirring. The reactionmixture was transferred to a 300 ml. Parr reactor, which was then purgedwith nitrogen for about 30 minutes, and then the reactor was fullyclosed and heated to 140° C. for a four hour reaction period. Thereaction product was substantially in latex form and analysis indicatedthat a degree of tagging had been accomplished, together with apost-polymerization transamidation reaction with the taurine.

In the following Examples 42 to 45, the fluorescent derivatizing agentsused were sulfanilic acid (4-aminobenzenesulfonic acid) and anthranilicacid (ortho-aminobenzoic acid or 2-aminobenzoic acid), and in someinstances a concommitant post-polymerization derivatization with sodiumformaldehyde bisulfite was conducted.

EXAMPLE 42

80 grams of an aqueous solution containing 35 weight percent of anAcAm/AA copolymer (50/50 mole percent, having a weight average molecularweight of about 13,000) was admixed with 0.69 grams of sulfanilic acid,and the admixture was transferred to a 300 ml. Parr reactor, which wasthen purged with nitrogen for about 30 minutes, and then sealed andheated to 150° C. for about 5 hours. The analysis of the reactionproduct indicated that a degree of fluorescent tagging of the polymerhad occurred.

EXAMPLE 43

Example 42 was repeated except the sulfanilic acid charge was reduced to0.67 grams, 11.22 grams of 93.5% HOCH₂ SO₃ Na was added to the reactionmixture, and the reaction temperature-was reduced to 137° C. Analysis ofthe reaction product indicated that both derivatization reactions hadoccurred to some degree.

EXAMPLE 44

Example 43 was repeated except that 0.67 grams of anthranilic acid wassubstituted for the sulfanilic acid charge. Analysis of the reactionproduct indicated that both derivatization reactions had occurred tosome degree.

EXAMPLE 45

150 grams of the 35% polymer solution described in Example 42 above wasadmixed with 1.26 grams of anthranilic acid, transferred to a 300 ml.Parr reactor, which was then purged with nitrogen for about 30 minutes,sealed, and heated to 138° C. for 5 hours. Analysis of the reactionproduct indicated that the fluorescent tagging of the polymer hadoccurred to some degree.

It has been generally observed that the fluorescent intensities of thepolymers prepared according to Examples 41 to 45 above were not asstrong as that seen from solution derivatizations using variousamino-naphthalene mono- and di-sulfonic acids, but such lesserfluorescent intensity is no deterent to the use of such polymers inapplications where the background fluorescent is less intense thancooling waters and/or where the polymers are used at higherconcentration levels than is typical for cooling water treatmentpolymers.

As discussed above, the successfully tagged polymers may bedistinguished from unreacted derivatizing agent because these specieshave different fluorescent spectra, that is, differentexcitation/emission wavelengths at major peaks. In addition, it has beendetermined that the wavelengths of major absorption peaks are notdependent upon pH, that is, do not change when varying the pH from about3 to greater than 5, while easily detectable shifts in the majorabsorption peaks occurs in the fluorescent derivatizing agent subjectedto such a pH variation, and hence monitoring major peakexcitation/emission wavelengths while so varying the pH of the medium inwhich the polymer and/or agent is disposed is another techniqueavailable for distinguishing these species.

INDUSTRIAL APPLICABILITY OF THE INVENTION

The present invention is applicable to any industry employing polymers,particularly water soluble polymers, wherein it is desired at times tohave at least some of such polymer tagged with fluorescent groups formonitoring purposes, such as the water treatment industry.

We claim:
 1. A method of preparing a polymer having pendant fluorescentgroups comprising:admixing an aqueous solution or latex of a polymerhaving pendant carbonyl-type groups of the Formula I ##STR6## wherein Ris --OR' or --NH₂, and wherein R' is hydrogen or a substituent otherthan hydrogen, and salts thereof and mixtures and combinations, thereof,with an amine-containing organic fluorescent composition of the FormulaIII ##STR7## wherein one of R₅ and R₆ may be hydrogen, and within atleast one of R₅ and R₆ or within R₅ and R₆ taken together is an organicfluorescent group; heating said admixture for a sufficient period oftime to accomplish a degree of (trans)amidation derivatization of saidpolymer; and wherein said admixture contains a formaldehyde-bisulfitepost-polymerization derivatization agent in addition to saidamine-containing organic fluorescent composition, and by said heatingfor said time period a post-polymerization derivatization reaction inaddition to said (trans)amidation with said amine-containing organicfluorescent composition is accomplished.
 2. The method of claim 1wherein said admixture is heated in a closed vessel at a temperature offrom about 120° to about 200° C.
 3. The method of claim 1 wherein saidadmixture contains at least 10 weight percent of said polymer.
 4. Themethod of claim 1 wherein said amine-containing organic fluorescentcomposition is admixed with said polymer in an amount of at least 0.01weight percent based on total weight of said polymer.
 5. The method ofclaim 1 wherein said (trans)amidation derivatization of said polymer isaccomplished to the degree of incorporating into said polymer at least0.01 weight percent of said amine-containing organic fluorescentcomposition.
 6. The method of claim 1 wherein said amine-containingorganic fluorescent composition contains a primary amine.
 7. The methodof claim 1 wherein said pendant carbonyl-type groups of said Formula Iof said polymer are contained in mer units of Formula II ##STR8##wherein R₄ is C_(n) H_(2n) wherein n is zero or an integer of from 1 toabout 10, R₁, R₂ and R₃ are independently hydrogen or a substituentother than hydrogen, R is as defined in Formula I, and salts thereof andmixtures and combinations thereof.
 8. The method of claim 1 wherein saidadmixture has a pH of from about 3 to about
 11. 9. The method of claim 1wherein said admixture is heated for a time period of from about 1 toabout 8 hours.
 10. The method of claim 1 wherein said admixture is anaqueous solution of said polymer at a concentration of said polymer offrom about 30 to about 40 weight percent, and said polymer has a weightaverage molecular weight of up to 100,000.
 11. The method of claim 1wherein said admixture is a water-in-oil latex of said polymer and saidpolymer has a weight average molecular weight of at least 200,000. 12.The method of claim 7 wherein said polymer contains at least 10 molepercent of said mer units of said Formula II.
 13. The method of claim 7wherein said polymer contains at least 50 mole percent of said mer unitsof said Formula II.
 14. The method of claim 7 wherein said mer units areunits of acrylic acid, acrylamide, salts thereof, or combinationsthereof.
 15. The method of claim 1 wherein one of R₅ and R₆ is hydrogenand the other is an (alkylene)aromatic ring system, which aromatic ringsystem may contain other substituents.
 16. The method of claim 15wherein said aromatic ring system is a polynuclear aromatic ring system.17. The method of claim 15 wherein said aromatic ring system containssulfonic acid, carboxylic acid, salts thereof, or a plurality thereofsubstituent(s).
 18. The method of claim 15 wherein said aromatic ringsystem is a naphthalene ring system having from 0 to 3 sulfonic acidsubstituents or salts thereof.
 19. A method of preparing a polymerhaving pendant fluorescent groups comprising:admixing an aqueoussolution or latex of a polymer having pendant carbonyl-type groups ofthe formula I ##STR9## wherein R is --OR' or --NH₂, and wherein R' ishydrogen or a substituent other than hydrogen, and salts thereof andmixtures and combinations thereof, wherein said pendant carbonyl-typegroups are contained in mer units of Formula II ##STR10## wherein R₄ isC_(n) H_(2n) wherein n is zero or an integer of from 1 to about 10, R₁,R₂ and R₃ are independently hydrogen or a substituent other thanhydrogen, R is as defined in Formula I, and salts thereof and mixturesand combinations thereof, with an amine-containing organic fluorescentcomposition of the Formula III ##STR11## wherein one of R₅ and R₆ may behydrogen, and within at least one of R₅ and R₆ or within R₅ and R₆ takentogether is an organic fluorescent group; heating said admixture for asufficient period of time to accomplish a degree of (trans)amidationderivatization of said polymer; and wherein said admixture contains aformaldehyde-bisulfite post-polymerization derivatization agent inaddition to said amine-containing organic fluorescent composition, andby said heating for said time period a post-polymerizationderivatization reaction in addition to said (trans)amidation with saidamine-containing organic fluorescent composition is accomplished. 20.The method of claim 19 wherein n is zero or 1, R₁ and R₃ are hydrogen,R₂ is hydrogen or methyl or --CO2H, R is --NH₂ or --OR' wherein R' ishydrogen or methyl, and salts thereof and mixtures and combinationsthereof.